⬆️ Bump furo from 2023.5.20 to 2023.9.10

Bumps [furo](https://github.com/pradyunsg/furo) from 2023.5.20 to 2023.9.10.
- [Release notes](https://github.com/pradyunsg/furo/releases)
- [Changelog](https://github.com/pradyunsg/furo/blob/main/docs/changelog.md)
- [Commits](pradyunsg/furo@2023.05.20...2023.09.10)

---
updated-dependencies:
- dependency-name: furo
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

pyproject.toml

@@ -45,7 +45,7 @@ firecrest = "aiida_firecrest.transport:FirecrestTransport"
 
 [project.optional-dependencies]
 dev = ["pytest", "pytest-cov", "pytest-regressions", "pytest-timeout", "pgtest"]
-docs = ["furo==2023.5.20"]
+docs = ["furo==2023.9.10"]
 
 [tool.flit.sdist]
 exclude = [